get_market_index

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It does disclose that these are real-time quotes (data freshness) and what happens when codes is omitted, which is meaningful behavioral context. It says nothing about auth, rate limits, delay, or response shape, so it is adequate but incomplete for a no-annotation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The purpose is front-loaded in one line, followed by a compact Args block. Every sentence carries information, though the repeated index list (once in the purpose, once in the default description) is slightly redundant.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With only one optional parameter, an output schema present (so return values need no explanation), and no annotations, the description covers what the agent needs to call it correctly. The remaining gap is the lack of any note on data freshness guarantees or error behavior.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate, and it largely does: it marks codes as optional, specifies comma-separated syntax with a concrete example ('sh000001,sz399001'), and defines the default set when blank. It stops short of explaining the code format rules in full, hence not a 5.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (获取/get) and resource (A 股大盘指数实时行情) and enumerates the concrete indices returned (上证指数、深证成指、创业板指、沪深300). The resource type is clearly distinct from the sibling stock tools (get_stock_quote, search_stock, etc.), so an agent can tell it apart without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the resource type: fetch market-index quotes. The description also clarifies the default behavior when codes is empty, which is helpful context. However, it never explicitly states when to prefer this over the sibling stock-quote tools or any conditions/exclusions, leaving the routing to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.